Field of the Invention
The present invention relates to an internal combustion engine.
Description of the Related Art
In diesel engines, so-called boot-type injection is known in which fuel injection is executed with lowered injection rate and subsequently another fuel injection is executed with elevated injection rate. By executing this boot-type injection, burst combustion of fuel can be prevented, and thereby generation of NOx can be reduced and combustion noise can be restrained. In this regard, a technique is known that executes fuel injection in a continuous manner by, during execution of fuel injection with low injection rate in the boot-type injection, moving a needle up or down through intermittent supply of command signal to a fuel injection valve and moving the needle up before it is moved down to the full extent (that is, before the valve is closed) (see Patent Document 1, for example).